It depends on what you’d like to see and to do in Ba Be?
From October to August is best time for travellers who want to trek in Ba Be. Because the weather is not too hot, 8oC to 25oC, it’s very suitable for trekking. The lowest temperature in Ba Be is 7 oC.
If you want to see rice fields at their best, April to May and September to October is the best time for you.
If you want to swim or kayak on Ba Be lake, the best time is from August to October. The temperature is from 18oC to 32oC.